Seat ring for rotary valves



N. B. NEw'roN 2,297,161

' SEAT' RING `FOR ROTARY vALvE's sept. 29, 1942.

Filed Aug. g5. 1941 Patented sept. 29, 1942 sEA'r nING Fon ao'rAaY vALvEs Norman B. Newton, Chicago, Ill., assigner to Crane Co., Chicago, Ill., a corporation of Illinois Application August z5, 1 941, serial No. 408,165 Claims. (Cl. 251-113) 'Ihis invention relates to a new and improved form of seat ring for rotary valves in which the latter employ a spheroidal type of closure member. It has for one of i-ts principal objects the provision of a concavo-convex ring of exible, elastic material, the mounting thereof within the casing providing that the seat ring is substantially flattened uponassembly with the closure member thus providing a greater bearing load at its outer periphery.

An important object of this invention is to provide novel valve seats having relatively small areas of contact or bearing surfaces with the closure member with the result that large bearing loads are applied to relatively small areas and thus tend to .improve the valve seat tightness.

Another important object of this invention is the provision that with a substantial portion of the bearing load on the outside periphery of the seat rings it is possible for the inlet seat to be pressure tight especially under relatively low pressures.

A still further important object oi this invention is to provide rubber or composition seat rings capable of a iiexibility that permits greater tolerances in machining of the body and disc without impair-ing valve seat tightness. g Other and further important objects ofthis invention .will become apparent from the disclosures in the following specification read )with the accompanying drawing, in which Fig. 1 is a vertical sectional view of a valve employing the principles of my invention.

Fig. 2 is a view similar to Fig. 1 with the spherithe inlet 4 with the outlet 6. The spherical disc 1, at its upper portion, is provided with a polygonally shaped socket 9 into which sets the simiwith the customary packing I4 and the packing cal closure member rotated through an arc of 90 I As shown in the drawing, the reference numeral I indicates generally the body or casing portion of a valve. having a bonnet 2 bolted to the body I by means of the bolts 3. The body I has the usual inlet 4 and the outlet 6. 'I'he valve of this invention comprises a spherical form of disc or plug closure member 1, the latter having an aperture 8 therethrough adapted to connect nut I6.

The seat rings of this invention composed of rubber or other suitable material shown at I1 and I8 are preferably molded in the concavoconvex shape as shown by the dotted lines in the assembly, Fig. 1, or as shown more clearly in the modifications illustrated in Figs. 4, 6 and 7. Obviously, the seat ringsy I1 and I8 can be made of rubber,'synthetic rubber or any other material having similar flexible elastic characteristics. The body I is provided with annular recesses, as shown at I9 and 2|, for the reception of the seat rings I1 -and Il. The ends of the seat rings I1 and I8 may be rounded as shown at 22. In actual practice, the closure member 1 need not be a perfect sphere inasmuch as the diameter through the aperture 8 is less than the diameter perpendicular to the aperture 8 as it is shown in Fig. 2. Before installation of the spherical plug 1 the rubber seat rings I1 and I8 extend into the space to be occupied by the closure member 1- as shown by the dotted lines in Fig. 1.

The disc 'I ls assembled with the casing l by being inserted from the top and before 4the bonnet has been placed in position and when the aperture 8 through the sphere is in the position shown in Fig. 1. -The spherical form of the closure member is thus capable of spreading the rubberseat rings toward a flattened position within the body. The latter flattening produces an increased diameter in the rings, making a fluid-tight seal at the outer periphery of the rings between the curved or rounded ends 22 and the annular recesses or shoulders I9 and 2l'. Inasmuch as the rubber seat rings are molded in the concavoconvex form, as shown by the dotted lines, they will always tend to resume that original. shape. Therefore, the tendency of the rubber seat rings is to assume theshape as shown by the dotted lines and in so ldoing make a fluid-tight seal with the closure member 1.' The polygonal socket connection between the stem and the closure member, as shown at 9 and II, is relatively loose thus allowing the spherical closure member 1 to have lateral motion as originated by line pressures. When the spherical disc 'I is rotated sphere increases the load on Athe rubber seatl rings thus further. insuring a fluid-tight valve.

Figs. 4, 5, 6 and 7 show modied forms of rubber seat rings all of which are adaptable to the valve assembly shown in Fig. 1. The modified seat rings as shown in Figs. 4, 6 and '1 are molded in a similarly concave-convex shape as shown by the seat rings I1 and Il of Figs. 1 and 2. Fig. 4 shows a rubber seat ring diering from the seat ring l1 in that the outer periphery is not rounded but at as shown at 23. Fig. 5 is a plan view of the ring shown in Fig. 4 having an aperture 28 and the at annular periphery 23. The rings shown in Figs. 6 and 7 are modifications having reinforcing metallic springs 21 and 28, respectively. The metallic spring 21 is very small and' does -not extend over the entire length of the rubber seat ring as does the spring 28. I'he inserted spring washers 21 and 28 can be of any desired curvature and strength and willI aid in the tendency of the rubber to assume its original molded shape.

In valves of this type it is generally believed that only the outlet should be pressure tight and not both the inlet and outlet. However, in this novel construction the spring tendencies of the seat ring constantly seal both inlet and outlet regardless of the line pressure which tends to move the disc 1 laterally against the outlet seat ring and thereby seal it tighter at the latter location than at the inlet 3; but in no instance is the inlet seat ring entirely disengaged from either the closure member 1 or the outer shoulder in the body itself. Therefore the tendencies of this valve will be'to eliminate any line iluid from circulating around the peripheral surfaces of the sphere or closure member 1. This provision, however, is not important to the operation as packing is employed in the bonnet to prevent any leakage therethrough if the inlet side of the valve should allow leakage of line fluid.

Because of the unique construction employed, much greater tolerances are permissible in the machining of the body of this valve and also of the spherical disc 1 than in any previousvalves of this type employing flat seat rings.. The

ilexible elastic qualities of the seat rings make it possible to have a iluid-tight valve without the expensive machining operations ordinarily accompanying the manufacture of such a valve. My novel seat arrangement makes the valve relatively cheap to manufacture; it is always iluid tight, has seats that are readily renewable and effects complete opening of Vthe valve within a quarter turn of thehandle.

It is obvious that numerous changes can be made without varying from the principles deinwardly at their central portions toward each other, a spheroid formed closure member having inlet and an outlet, the housing having annulary recesses associated with the said inlet and outlet, exible seat rings positioned within each of said recesses, "the said seat rings being convexly formed with respect to the center of the valve, a spheroid plug closure member having an opening therethrough positioned centrally of the two seat rings and spreadi! I each of the said seat rings into an abnormal fiat position, the said seat rings forming a resilient seal with the plug closure member and with the recesses in the said housing at the outer peripheries of the said seat rings.

3. A valve comprising a casing having an inlet and an outlet, internal annular recesses in the said casing associated with the said inlet and 'the said outlet, ilexible seat rings' adapted to fit within the said annular recesses, the said seat rings being initially reinforced and molded into a concavo-convex shape and placed in the recesses so that their apertured convex portions oppose each other to restrict the size of the opening between the inlet and the outlet, a spheroidal closure member having an aperture therethrough placed between the inwardly extending face portions of the seat rings and tending upon assembly with said casing tolilatten the said seat rings against the said recesses, the

outer peripheries of the said seat rings being rounded to contact with the bottom and peripheral portions of -izhe said recesses.

4. A valve comprising a casing having an inlet and an outlet, annular recesses in the said casing associated with the said inlet and the said outlet, ilexible dished seat rings adapted to fit within the said annular recesses and positioned in the recesses so that their projecting portions face each other to restrict the opening between the inlet and the outlet, a spheroidal type closure member having an aperture therethrough and assembled within the casing to hatten the said seat rings in a -washer-dike form, the outer peripheries of the said seat rings being relatively flat to iit the corner portions of the said recesses.

5. A valve comprising a casing having an inlet and an outlet, annular recesses internally of the said casing associated with the said inlet and outlet, rubber seat rings adapted to nl;l within the said annular recesses, the said rubber seat rings molded in a ooncavo-convex shape, the said rlngsplacedintherecessessothattheirenlarged central portions face each other restricting the size of the opening between the inlet and the outlet to a minmium, a plug type closure member having an aperture therethrough and placed between the inwardly facing seat rings scribed in this specification and I therefore do an inlet and an outlet, flexible elastic seat rings 7 mounted in the said body, the said exible elastic seat rings having a normal contour projecting tendingtoflattentheseatrlngsagainstthebottom. faces of the said recesses, a reinforcing metallic element within said body seat rings whereby the said element acts to continually force the seat ring to assume its original concavoconvex shape.

. NORMAN B. NEWTON. 

